LTheobald

There most definitely is still a market for people making desktop applications. Take Sparrow (http://sparrowmailapp.com/) for example. They seemed to be doing well for a desktop application - so well they got acquired by Google. An number of other applications I have purchased on my Mac are done by small teams: Alfred, 1Password, TextExpander, Things, Coda, Tweetbot. As other comments have mentioned, it may be easier on the Mac due to a perceived higher quality & richer client base. Independent games are also doing very well. Look at games like Braid & Limbo (true these also were XBLA titles). Games are still desktop applications after all.

So yes, I'd say there most definitely is a market for desktop apps & I wouldn't be surprised if the market was the strongest it had been for a while with the rise of the Mac App Store.

I used MongoDB to handle analytics for our system and it's been OK. We had some problems with memory leaks & other issues with Mongo but as new versions are released, these problems are fixed.

As for the question "Why MongoDB?" it depends on what you want MongoDB to do. Each of the NoSQL solutions have their pros and cons and you'll be best doing some investigation into what best suits your purposes. For example, CouchDB has built in record versioning. For analytic's this is an unwanted overhead but for a system where you need record history (e.g. collaboration tool) having that built into your DB is a big boost.

Then there's also the CAP Theorem. Check out this URL for a great overview: http://blog.nahurst.com/visual-guide-to-nosql-systems. Out of consistency, availability and partition tolerance, you can only satisfy 2 of the three. So for example, your solution could partition beautifully and every client could read/write data when you want but at the same time you couldn't guarantee every client sees the same data all the time.

Hope that gives you a little food for though. MongoDB's great. The community is helpful, the product is quick & easy to get up and working with and it's powerful to boot. But it's not the only solution out there and the right solution depends on what you are aiming for.